1. Field of the Invention
This present invention relates to substrate processing and, in particular, to methods and apparatus for conditions within a substrate processing system.
2. Description of the Related Art
Semiconductor devices, such as transistors, diodes, and integrated circuits, are typically fabricated on a thin slice of semiconductor material, termed a substrate or wafer. The substrate is fabricated within a substrate processing station, which typically includes one or more load locks, a wafer handling module and one or more processing modules. The one or more load locks provide a substantially particle free environment from which substrates may be selectively withdrawn into the substrate handling module. The substrate handling module typically includes a substrate handler, which is configured to move substrates to/from the one or more load locks and to/from the one or more processing modules.
There are several general problems that are associated with prior art substrate processing stations. For example, as the substrate is moved within the processing station, the substrate can become misaligned or mispositioned for various reasons. Such mispositioning can result in damage to the substrate as it is moved within the processing station and/or our errors in the fabrication process if the mispositioning occurs within a processing module. As such, some substrate processing system include several sensors to. monitor the position of the substrate position within the processing station. Each sensor adds to the complexity and cost of the processing station. These sensors are also typically difficult to maintain.
The information gathered by the sensors is typically transmitted to a control system that is positioned outside of the processing station. The information is usually transmitted through wires that extend through holes formed in the walls of the processing station. To preserve the particle free environment within the processing station, each hole must be suitably sealed. In addition, the sensors may require power. Traditionally, the power has been provided by wires that must also extend through holes formed in the walls of the processing station. In other arrangements, the sensors may be powered by batteries placed in the sealed environment. However, the batteries must be periodically replaced, which can be costly and time consuming.
A need therefore exists for a more simple and accurate method for monitoring the position of the substrate within a processing station.
One aspect of the present invention is a substrate processing system for processing a substrate. The processing system comprising a plurality of chamber walls, which define a substantially sealed environment. A sensor is positioned in the sealed environment. A power source is also positioned in the sealed environment. In some embodiments, the power source comprises a photoelectric cell.
Another aspect of the present invention is a method for monitoring conditions within a substantially scaled environment of a processing system. The method comprises providing a sensor and a wireless transmission device inside the sealed environment, collecting information from the sensor, and transmitting the information from the sensor with the wireless transmission device to a device located outside of the sealed environment.
Another aspect of the present invention is a substrate processing system for processing a substrate. The processing system comprises a plurality of chamber walls, which define a substantially sealed environment. A sensor is positioned in the sealed environment. A wireless transmission device is positioned within the sealed environment and is configured to transmit information outside of the sealed environment.
Yet another aspect of the present invention is method for monitoring conditions within a substantially sealed environment of a processing system. The methods comprises providing a sensor and a photoelectric cell inside the sealed environment, collecting information from the sensor, and providing power to the sensor from the photoelectric cell.
Further aspects, features and advantages of the present invention will become apparent from the following description of the preferred embodiments.